We are studying some of the factors which affect the rate of protein catabolism in normal and dystrophic muscle tissue. We are studying the following aspects: (a) are acetylated proteins normally present in muscle catabolized at the same rate as nonacetylated proteins in both normal and dystrophic muscle? (b) does dystrophic muscle contain unusual levels of enzymes capable of removing N-acetyl groups from muscle proteins? (c) does the addition or deletion of N-acetyl residues from a protein alter its catalytic and functional properties? (d) can we isolate and chracterize enzyme systems which are capable of adding or removing such acetyl groups from muscle proteins? and (e) are proteins present in dystrophic muscle acetylated to a lesser extent than those present in normal muscle?